Just in time for that annual fourth of July cookout in which you drag all that filthy white lawn furniture from its molding, mildewing stack out behind the shed: a team from Germany’s Fraunhofer Institute has created a titanium dioxide-doped polymer coating that kills germs and bacteria when exposed to sunlight. Self-cleaning lawn furniture surely can’t be far behind.
The coating works due to an electrochemical reaction that kicks in when ultraviolet light from the sun hits titanium dioxide, producing free radicals. These molecules with unpaired electrons at the surface have a tendency to degrade cell walls along with the DNA inside. Bacteria or fungi--and the black, grimy residues they create on your lawn furniture--are thus destroyed. Fraunhofer says the formula has so far been proven effective against 30 different kinds of bacteria and fungi.
Beyond furniture, the coating is also effective at keeping glass free of fingerprints, which disappear after just an hour of exposure to sunlight. Picture exterior windows that clean themselves daily or smartphones that lose their smudges in sunlight.
Five amazing, clean technologies that will set us free, in this month's energy-focused issue. Also: how to build a better bomb detector, the robotic toys that are raising your children, a human catapult, the world's smallest arcade, and much more.